1. Impacts of Salinity on El Paso’s Surface Water Supply presented at the Annual Salinity Management and Desalination Summit December 8, 2003 Michael P. Fahy Planning and Development Manager

2. Colorado New Mexico Texas United States Mexico Taos Santa Fe Albuquerque Socorro Las Cruces El Paso Juarez Ft. Quitman Rio Grande Texas Colorado New Mexico

4. Rio Grande Project Bureau of Reclamation Project (1916) Extends from Elephant Butte Lake in New Mexico to Fort Quitman in Texas 90,500 irrigated acres in New Mexico Originally 69,010 irrigated areas in Texas During full allocation years, Bureau delivers 931,841 AF at canal headings with Reservoir release of 790,000 AF

5. Rio Grande Project (con’t) Encroachment by urbanization in both states Complex systems of diversion dams, canals, laterals and agricultural drains Agricultural and municipal releases are made from March through September during full allotment years, shorter period during droughts

6. Elephant Butte Reservoir Average Elev. Spillway Elev.

7. History of Agricultural Drains Project was originally constructed without drains Drains were constructed in the 1930’s to improve drainage, mitigate saturated soil conditions, and generally improve crop production Excavated between fields, 8 to 12 feet deep, variable width depending on flow capacity All drains eventually discharge back into the river

8. Del Rio Drain East Drain Picacho Drain La Mesa Drain Montoya Drain Rio Grande Project Major Drains in Mesilla Valley River Points of Entry New Mexico Texas

9. Rio Grande Anthony Franklin Mts. McCombs Canutillo NEW MEXICO TEXAS Vinton Railroad Dr. Dyer St. Transmountain Doniphan USA MEXICO Ciudad Juarez Montana Yarbrough Zaragosa Airport Americas Ave. Alameda  Fort Bliss Military Reservation Sunland Park Mesa Dr. Rio Grande N Water System Robertson/Umbenhauer Water Treatment Plant North-South Freeway Jonathan Rogers Water Treatment Plant Elephant Butte

10. Source - Rio Grande Conveyance System Water Management and Source Water Protection Study Part 1 Data Evaluation Report Boyle Engineering Corporation / Parsons Engineering Croporation, Inc. March 1997

11. Note: Average Individual Annual Drain Flows Range from 25 to 65 cfs

12. Rio Grande Average Monthly TDS Concentrations at American Diversion Dam Under Current Conditions Month % Exceedance TDS (mg/L) 1461 1313 744 784 836 786 819 844 1005 1302 1459 1461 TDS Limit Ref: Boyle-Parsons Drain Mitigation Report to the NM-TX Water Commission (1998)

13. Sulfate Limit Rio Grande Average Monthly Sulfate Concentrations at American Diversion Dam Under Current Conditions Month % Exceedance Sulfate (mg/L) 478 430 245 260 277 260 271 279 331 427 478 Ref: Boyle-Parsons Drain Mitigation Report to the NM-TX Water Commission (1998)

14. El Paso’s Current Methods for Planning and Operation of Two Water Treatment Plants Routine monitoring of water quality at canal diversions Plants are shut down when sulfates near 300 ppm or TDS approaches 1000 ppm Routine flow monitoring at upstream gauging stations Regular communications with irrigation districts and Bureau of Reclamation regarding release orders and water quality

15. El Paso’s Current Methods for Planning and Operation of Two Water Treatment Plants (con’t) Conductivity meters have been installed in the Rio Grande and within four drains at the state line Intent is to provide continuous, “real-time” water quality monitoring with approx. 1-day lead time to El Paso EPWU provides financial support for the newly formed Paso del Norte Watershed Council with established goal of improving river water quality

16. El Paso’s Current Methods for Planning and Operation of Two Water Treatment Plants (con’t) East Drain West Drain Rio Grande @ Anthony Bridge Newmexas Drain Anthony Drain EPWU/EBID Conductivity Probes

17. Potential Longer-Term Techniques for Managing Salinity Studies conducted as part of the Regional Sustainable Water Projects of the NM-TX Water Commission: Retire agricultural land/manage saline lands Treat drain flows Dilute drain flows with ground water

18. Potential Longer-Term Techniques for Managing Salinity (con’t) Impound and release drain flows Relocate point of discharge for critical drains Relocate water plant diversion locations Costs for some of these alternatives range from $1.0 million to more than $15.0 million Most require approval by agencies with jurisdictional authority

19. Questions ?